Influence of age at diagnosis and duration of diabetes on the positivity of glutamic acid decarboxylase antibody in South-Brazilian type 1 diabetes mellitus.

Aim: To evaluate the influence of age of onset and duration of diabetes on the positivity of glutamic acid decarboxylase antibody (GADA) in South-Brazilian type 1 diabetes mellitus (DM) patients.

Methods: GADA was evaluated in 92 patients with type 1 diabetes, in 147 gestational DM patients, and in 59 subjects with normal glucose tolerance.

Results: Type 1 patients with positive GADA (N = 44, 48%) were older at the onset of diabetes (22 ± 9 versus 18 ± 10 y, P = 0.

Diabetes mellitus classification.

The right classification for diabetes mellitus (DM) allows a more adequate treatment and comprises four categories: type 1 DM, type 2 DM, other types, and gestational diabetes. In some cases, there might be a superposition of situations, especially with regard to the DM that initiates in the young adult or is initially presented with diabetic ketoacidosis intermediately to type 1 and 2 DM. Thus, additions to the classic classification system have been proposed as assessing the presence of autoimmunity (antibody) and b cell function (C-peptide) to precisely define the subtypes.